FOXBOROUGH, Mass. -- After previously saying that he didn't plan to coach into his 70s, Bill Belichick is leaving the door open to do so.

"When I said it, maybe I didn't know what 70 felt like," the New England Patriots coach said Monday during his weekly appearance on sports radio WEEI. "So I'm not really sure if that's an accurate statement today or not. At the time, I didn't feel that way. Now that I'm closer to that age, I don't know."

Belichick, 67, recorded his 300th career win as a head coach on Sunday (regular season and postseason combined). He joins Don Shula (347) and George Halas (324) as the only head coaches to reach that milestone.

If Belichick plans to stop coaching by his 70th birthday, it would make it very difficult to catch Shula on the all-time wins list.

In the 2009 documentary "A Football Life: Bill Belichick," he had said he didn't plan to follow in the path of longtime Buffalo Bills coach Marv Levy, who had coached into his 70s. Whenever questions about how much longer Belichick might coach have come up since, that remark was often used as a benchmark for any timelines, with Belichick himself deflecting the topic. But there have been hints in recent years that Belichick has softened his stance.

When it was mentioned to Belichick in the radio interview Monday that he could be a "young 80," he said, "that sounds good. Be a young anything." That seemed to be a reference to a book Belichick previously told WEEI that he enjoyed in a recent summer: "Younger Next Year," written by Dr. Henry S. Lodge and Chris Crowley.

Belichick has also spoken in recent years about how much he enjoys having his sons, Steve and Brian, on the Patriots' coaching staff. Steve is in his eighth season with the club, currently in serving as safeties coach. Brian is in his fourth season on staff, currently a general coaching assistant.